The white rhinoceros (Ceratotherium simum,) or square-lipped rhinoceros, is the second largest land mammal on the planet. Distinguished from the black rhinoceros by its wide, flat lip, the white rhino is perfectly built for grazing upon grasses and leaves while holding its face parallel to the earth. Two subspecies are recognized, the Southern White Rhino, (C. s. simum,) with populations in southern Africa listed as “Near Threatened” on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, and the Northern White Rhino, (C. s. cottoni,) a “Critically Endangered” variation nearly extinct in the wild.